Vehicle-towed agricultural implements are commonly employed to efficiently accomplish a wide variety of farming tasks, such as cultivating and seeding. These implements may be very wide, so as to cover a large swath of land with each pass of the implement, thereby reducing the number of passes needed and accordingly reducing the amount of time needed to accomplish a given farming task.
Generally, wide agricultural implements present at least two well-known design considerations. Some operations, such as crop seeding, require a relatively high degree of precision. Small grain seeds, for example, must be within fractions of an inch of a recommended depth to achieve proper growth and best yield. To achieve the requisite degree of precision, an agricultural implement must be capable of accurately following what may be slightly uneven ground across the width of the implement.
Agricultural implements must also be efficiently transportable between fields that may be separated by miles. Moreover, the fields may be fenced, and accordingly, the implement must be capable of passing through narrow fence gates without undue difficultly.
These design considerations have typically dictated that wide agricultural implements be configured with a center section having one or more wing sections extending laterally outward from each side. The wing sections are coupled so as to enable some degree of independent vertical movement of the wings relative to the center section as the implement passes over uneven ground. Also, the wings are usually positionable in a folded arrangement to enable the implement to be transported over a public road or to negotiate a narrow fence gate. Examples of implements with various prior folding wing arrangements are described in U.S. Pat. Nos. 3,669,195; 4,050,523; 4,415,043; 4,467,875; 4,576,238; 4,683,957; 4,878,545; and 6,125,775, all of which are hereby fully incorporated herein by reference.
A recent trend in agriculture is toward minimal-till or no-till planting methods. In such methods, where extensive cultivation is not used to break-up the soil and to disperse crop residue material from the previous season, the seed planter implement may need to be capable of supplying significant down pressure to planter units. Typically, down pressure is supplied by weight of the wing sections and other portions of the seeder implement. As a consequence, the folding portions of the seed planter implement need to be structurally capable of handling significant loads imposed by the weight of the wing sections.
Previous folding wing seed planters and other such implements typically have a relatively wide center section fitted with tool assemblies, and single-pivot folding wings on each side with tool assemblies on each. While such a configuration is simple and provides relatively good ground-following characteristics, the center section tool assemblies are typically not easily repositionable for transport. As a consequence, ground clearance is limited at the center section during transport, and the tool assemblies may be subject to damage from ground contact. If repositioned for transport, the center section tool assemblies may require extensive readjustment prior to the next use. Other previous folding wing mechanisms used in agricultural implements often have complex arrangements of pivots and linkages not easily adapted for the high loads and resultant stresses of no-till seed planter equipment and other high load applications.
What is still needed in the industry is a towed agricultural implement suitable for high load applications and having a simple and efficient means for repositioning tool assemblies for transport.